Additives for fuels

ABSTRACT

The present invention provides hydrocarbylaminomethylenesulfonic acid additives for hydrocarbonaceous fuels. These additives are the reaction products produced by sulfoalkylating certain hydrocarbyl-substituted amines. The sulfoalkylation is accomplished by reacting the hydrocarbyl-substituted amines with certain carbonyl compounds and sulfur dioxide. The hydrocarbyl substituent contains at least about 30 carbon atoms.

United States Patent [191 Coon [451 Oct. 29, 1974 ADDITIVES FOR FUELS [75] Inventor: Marvin V. Coon, Vallejo, Calif.

[73] Assignee: Chevron Research Company, San

Francisco, Calif.

[22], Filed: Oct. 24, 1972 [21] Appl. No.: 296,373

[52] U.S. Cl. 44/72 [51] Int. C1 C101 1/24 [58] Field of Search 44/72, 73; 260/513 N [5 6] References Cited UNITED STATES PATENTS 1,944,300 1/1934 Ott et al 260/513 N 2,582,733 i/l952 Zimmer et al. 44/72 2,906,613 9/1959 Mills 44/72 2,923,611 2/1960 Wieiand 44 72 Primary Examiner-Daniel E. Wyman Assistant Examiner-Y. H. Smith Attorney, Agent, or FirmG. F. Magdeburger; C. J. Tonkin; S. R. La Paglia 6 Claims, No Drawings ADDITIVES FOR FUELS BACKGROUND OF THE INVENTION Field of the Invention The smooth and efficient operation of internal combustion engines with minimum pollution requires a high degree of cleanliness in the fuel intake system, valves, cylinders, piston heads and crankcase. Consequently, additives are incorporated into fuels to reduce deposits in the intake system and other engine parts. By maintaining various engine parts in clean condition, such additives reduce incomplete combustion, contribute to longer engine life and improved fuel performance, and reduce the production of pollutants.

SUMMARY OF THE INVENTION The reaction product of certain hydrocarbylsubstituted amines with certain aldehydes or ketones and sulfur dioxide yields hydrocarbylaminomethylenesulfonic acid additives for hydrocarbonaceous fuels. The hydrocarbyl substituent contains at least 30 carbon atoms and preferably less than 300 carbon atoms and is an aliphatic, alicyclic, aromatic group, or combination of these. The aldehyde or ketone is chosen from low molecular weight carbonyl compounds in the class of aldehydes and methyl ketones. Aldehydes are preferred, especially acetaldehyde, and most particularly formaldehyde.

DETAILED DESCRIPTION OF THE INVENTION I-Iydrocarbylaminomethylenesulfonic acid obtained as the reaction product of hydrocarbyl-substituted amines with certain carbonyl compounds and sulfur dioxide are fuel additives capable of providing superior engine cleanliness.

Hydrocarbyl, as used herein, denotes. an organic radical composed of carbon and hydrogen (except for minor, sometimes adventitious amounts of other elements such as oxygen), which may be aliphatic, alicyclic, aromatic or combinations thereof, e.g. aralkyl. Preferably, the hydrocarbyl group will be relatively free of aliphatic unsaturation, i,e. ethylenic and acetylenic, particularly acetylenic. The hydrocarbyl substituents will contain at least 30 carbon atoms and preferably less than 300 carbon atoms. When the hydrocarbyl groups are of lower molecular weight, the average number of hydrocarbyl substituents in a given amine may be greater than one. The hydrocarbyl groups are preferably aliphatic, having preferably from O to 2 sites of ethylenic unsaturationand'most preferably from to 1 such site. Hydrocarbyl groups derived from a polyolefin, itself derived from olefins (normally l-olefins) of from 2 to 6 carbon atoms (ethylene being copolymerized with an olefin of at least 3 carbon atoms), or from a high molecular weight petroleum-derived hydrocarbons are preferred, and of these polyisobutene is most preferred.

The hydrocarbyl substituents will have molecular weights from 420 to about 10,000. Illustrative sources for the high molecular weight hydrocarbyl substituents are petroleum mineral oils, such as naphthenic bright stocks, polypropylene, polyisobutylene, poly-l-butene, copolymers of ethylene and propylene, poly-l-pentene, poly-4-methyll-pentene, polyl -hexene, poly-3- methylbutenel, etc. The molecular weights referred to herein are average molecular weights.

The hydrocarbyl-substituted amines are derived from monoamines and polyamines, preferably alkylene polyamines and polyalkylene polyamines by, for example, reaction of the halogenated hydrocarbon with the amine. Examples of such amines include methyl amine, ammonia, ethylene diamine, 2-aminoethyl piperazine, diethylene triamine, di(trimethylene) triamine, dipropylene triamine, triethylene tetramin'e, tripropylene tetramine, tetraethylene pentamine, pentaethylene hexamine, etc. The named amines encompass substituted and alkyl-substituted amines, e.g. N- methylethylene diamine, N,N'-dimethylethylene diamine, N,N-dimethylpropylene diamine, N- hydroxyethylethylene diamine, etc. Amines having up to about 68 amino nitrogens and up to about 20 carbon atoms are especially preferred. The hydrocarbylsubstituted amines are prepared, in general, by the reaction of a halogen-substituted hydrocarbon with the amine. Details of such preparations and further description of hydrocarbyl-substituted amines can be found in Honnen and Anderson US. Pat. No. 3,565,804.

The aldehydes and ketones which function together with sulfur dioxide as sulfoalkylating agents are chosen from low molecular weight carbonyl compounds in the class of aldehydes and methyl ketones. Aldehydes are preferred, especially acetaldehyde and most particularly formaldehyde, for ease of reactivity. Examples of such carbonyl compounds include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, acetone, methylethyl ketone, etc.

The hydrocarbyl substituents in the hydrocarbylsubstituted polyamine can be found at any nitrogen atom which is capable of receiving it, since these nitrogen atoms are in general inequivalent by symmetry, the expression of the substituted polyamine in terms of a given chemical structure is impractical. In general, the substituted polyamines which find use in this invention are mixtures of mono, and poly-substituted polyamines with hydrocarbyl groups substituted at various equivalent and inequivalent nitrogen atoms. The reaction which yields the hydrocarbylaminomethylenesulfonic acid of the present invention can occur at any nitrogen atom or at several nitrogen atoms in the same molecule. The sulfoalkylation can occur at primary, secondary and even tertiary amino nitrogen atoms. Consequently, it would be both impractical and confusing to try to express the general reaction product in terms of a single structure or class of structures. However, for the singular case of a mono-substituted monoamine, reacted with formaldehyde and sulfur dioxide, the proposed reaction scheme is believed to be expressible as:

R NI-I-CH SO I-I CH O S0 R-N-(Cl-I a )2 wherein R is the previously described hydrocarbyl substituent. It is believed that the hydrocarbylaminomethylenesulfonic acid exists as an internal salt, or zwitterion. Furthermore, the end products have molecular weights which are often higher than the starting hydrocarbyl-substituted amines. Consequently it is believed that some degree of dimerization, or trimerization, may occur.

Some hydrocarbylaminomethylenesulfonic acids produced from the sulfalkylation of a hydrocarbyl amine with formaldehyde and sulfur dioxide are N- hydrocarbylmethylamine-N-methylene-sulfonic acid, N-hydrocarbylethylenediamine-N-methylenesulfonic acid, N,N'-dihydrocarbyl-N-methyl-ethylenediamine- N-methylene-sulfonic acid, N,N'- dihydrocarbyldiethylenetriamine-N,N"-di(methylenesulfonic acid), N"-hydrocarbyltriethylenetetramine- N,N"'-di(methylene-sulfonic acid), etc. Some hydrocarbylaminomethylenesulfonic acids produced from the sulfalkylation of a hydrocarbyl amine with another aldehyde or methyl ketone such as acetaldehyde or acetone are N,N-dihydrocarbyl-N-methyldiethlenetriamine-N", N"di(methyl methylenesulfonic acid), N-hydrocarbyl-N-ethyl tetrapropylene pentamine-N", N"di(dimethyl methylene sulfonic acid), etc.

METHOD OF PREPARATION The method of preparation consists, in general, of first dissolving the hydrocarbyl-substituted amine in a suitable solvent and then contacting with S and a carbonyl compound. A variety of solvents may be found suitable including petroleum oils, or petroleum oils in combination with other solvents, hydrocarbons, particularly aromatic hydrocarbons such as benzene and xylene used alone in or in combination with other solvents, alcohols and ethers such as isopropanol and tetrahydrofuran, used alone or in combination with other solvents depending on the solubility of the reagents. The carbonyl compound, such as the preferred formaldehyde, can be added in solution to the reaction mixture followed by the introduction of the sulfur dioxide. Paraformaldehyde is considered equivalent to formaldehyde for these purposes.

Normally, the solution of hydrocarbyl amine is stirred and heated with the addition of aldehyde or methyl ketone for a period ofless than one hour at temperature of from 50-l00C. Sulfur dioxide is then introduced without additional heating until the temperature drops to about 50C. The product is diluted and washed with suitable solvents and then, normally, stripped of solvent. The synthesis of sodium aminomethylene-sulfonates has been reported in J. Amer. Chem. Soc., Vol. 77, p. 5512, (1955) by Lacoste and Martell. The following examples illustrate our method of preparation of the hydrocarbylaminomethylensulfonic acids.

EXAMPLE 1 Polybutenetetraethylene pentamine 100g, about 0.074 mol) of number average molecular weight about 1 190 is dissolved in 100ml of toluene and 50ml of isopropyl alcohol. The mixture is heated to 67C, followed by the addition of aqueous formaldehyde (37 percent aqueous solution, 1 1.6g, about 0.148 mol). Heating is stopped and the mixture is stirred for 4 minutes. Sulfur dioxide is introduced until the temperature dropped to 50C. The mixture is washed with water until the wash ings are neutral, followed by stripping on the solvent stripper to yield 100.5g of resinous material having the following analysis: N, 3.55; S, 3.56; base number, 25mg KOH/g'; molecular weight, 3070.

EXAMPLE 2 Polybutenyltetraethylenepentamine (100g, about 0.074 mol) of average molecular weight 1190 is dissolved in ml of toluene and 50 ml of isopropyl alcohol. The mixture is heated to 67C, followed by the addition of aqueous formaldehyde (37 percent aqueous solution, 5.8g, about 0.074 mol). Heating is stopped and the mixture is stirred for 4 minutes. Sulfur dioxide is introduced until the temperature drops to 50C. The mixture is washed with water until the washings are neutral, followed by stripping on the solvent stripper to yield 94.0g of material having the formula analysis: N, 3.11; S, 2.45; base number, 55mg KOH/g; molecular weight, 2300.

EXAMPLE 3 Polyisobutenylamine (200g, about 0.048 mol) of average molecular weight 2070 is dissolved in 200 ml of toluene and 100 ml of isopropanol. The mixture is treated as in Example 1 using 4.4g of aqueous formaldehyde to give, after stripping on the solvent stripper, 200.4g of product having the following analysis: N, 0.50; S, 0.51; base number, 16 mg KOl-l/g; molecular weight, 4000.

EXAMPLE 4 Polyisobutenylethylenediamine (100g, about 0.056 mol) of average molecular weight of 1300 is dissolved in 100 ml of toluene and 50 ml of isopropanol. The mixture is heated to reflux (67C), and aqueous formaldehyde (38%, 4.4g, about 0.056 mol) is added. After 5 minutes, heating is stopped; and S0 is introduced until the temperature drops to 50C. The mixture is washed twice with 200 ml portions of water and 25 ml of butanol, then azeotroped to dryness, concentrated by distillation and stripped on the solvent stripper to yield 97.3g: N, 1.47; S, 1.31; molecular weight, 2950; IR, 1690(R N1-l 1235, 1040 cm (RSO H).

EXAMPLE 5 Polybutenylethylenediamine (800g, about 0.32 mo], 60 percent in xylene) of average molecular weight 1,300 is dissolved in 200 ml of toluene and 400 ml of isopropanol. The mixture is treated in the same manner as in Example 4 using 25.3g (0.32 mol) of aqueous formaldehyde to give 609g of material having the following analysis: N, 1.34; S, 1.51; base number, 9 mg KOH/g; molecular weight, 2000. 1

EXAMPLE 6 Polybutenylamine (206g, about 0.225 mo], 60% in xylene) of average molecular weight 820 is dissolved in 200 ml of toluene and 100 ml of isopropanol. The mixture is treated as in the last example using 17.7g (0.225 mol) of aqueous formaldehyde to yield 190.8g of product having the following analysis: N, 1.39; S, 1.43; base number, 7 mg KOH/g; molecular weight, 1240.

EXAMPLE 7 N-polypropenylethylenediamine (450g, about 0.05 mol) of average molecular weight 9,000 is dissolved in an aromatic solvent. The mixture is heated to reflux and 2.2g (0.05 mol) of acetaldehyde is added. S0 is then introduced until the reaction is completed. The product is washed with water and alcohol and then dried.

EXAMPLE 8 Polybutenyldiethylenetriamine (56 percent active material in xylene solvent, 1,000 g, 0.51 mol) of average molecular weight 1,450 is heated to 67C with stirring. Aqueous formaldehyde (37 percent aqueous solution, 41.3 g, 0.51 mol) is added to the flask. After about 3-4 minutes, S0 is introduced at a moderate rate until the temperature drops to 50C. An equal volume of hexane is added and the solution washed with water until the washings are neutral. Stripping on a solvent stripper gives 618 g of resinous light amber-colored material having the following analysis: N, 2.44; S, 2.15; Base No., 17.7mg KOl-l/g; molecular weight, 2920.

EXAMPLE 9 Polybutenyltriethylenetetramine (48 percent active material in xylene solvent, 700 g, 0.29 mol) of average molecular weight 1470 is reacted, as in the last example, with 37 percent aqueous formaldehyde (23.8 g, 0.29 mol) to yield 434 g of material having the following analysis: N, 2.86; S, 1.88; Base No., 21.9 mg KOH/g; moleculare weight, 2890.

EXAMPLE 10 Polybutenyltriethylenetetramine (57 percent active material in xylene solvent, 1,000 g, 0.35 mol) of average molecular weight 1730 is reacted, as in Example 8, with 37 percent aqueous formaldehyde (28.1 g, 0.35 mol) to yield 739 g of material having the following analysis: N, 2.61; S 2.13; Base No., 48.6 mg KOH/g; molecular weight, 3170.

EXAMPLE 1 1 Polybutenyltriethylenetetramine (213 g, 0.06 mol) of average molecular weight 3,550 is dissolved in an equal volume of toluene and reacted, as in Example 8, with 37 percent aqueous formaldehyde (4.6 g, 0.06 mol) to yield 186 g of resinous material having the following analysis: N, 1.31; S, 0.82; Base No., 4.6 mg KOH/g; molecular weight, 4045.

EXAMPLE l2 EXAMPLE 13 Polybutenylhydroxyethylethylenediamine 100g, 0.042 mol) of average molecular weight 1,600 is dissolved in 200 ml of hexane and reacted, as in Example 8, with 37 percent aqueous formaldehyde (3.5g, 0.043 mol) to yield 99.7g of product having the following analysis: N, 1.32; S, 0.67; Base No. 11 mg KOH/g; molecular weight, 2150.

EXAMPLE l4 Polybutenylmethylamine (100 g, 0.064 mol) of average molecular weight 1,470 is dissolved in 200 ml of hexane and reacted, as in Example 8, with 37 percent aqueous formaldehyde (7.15 g, 0.064 mol) to give 99.2 g of material having the following analysis: N, 1.12; S, 0.56; Base No., 15 mg KOH/g; molecular weight 2390.

EXAMPLE l5 Polybutenyldimethylamine (100 g, 0.075 mol) of average molecular weight 1,340 is dissolved in 200 ml of hexane and reacted, as in Example 8, with 37 percent aqueous formaldehyde (7.15 g, 0.064 mol) to give 102.8 g of material having the following analysis: N, 1.03; S, 0.91; Base No., 7 mg KOl-l/g; molecular weight, 2640.

COMPOSITIONS Depending on the particular application of the compositions of this invention, the reaction may be carried out in the medium in which it will ultimately find use and be formed in concentrations which provide a concentrate of the dispersant composition. Thus, the final mixture may be in a form to be used directly upon dilution in fuels. The hydrocarbylaminomethylenesulfonic acid additive will generally be employed inhydrocarbonaceous base liquid fuels. The additive may be formulated as a concentrate, using a suitable solvent, preferably, an aromatic hydrocarbon solvent, such as benzene, toluene, oxylene or higher boiling aromatics or aromatic thinners. Aliphatic alcohols of about 3 to 5 carbon atoms, such as isopropanol, isobutanol, n-butanol, and the like, in combination with hydrocarbon solvents are also suitable for use with the additive. Other polymeric materials may be used in conjunction with the additives of this invention in fuel compositions, e.g. polyisopropylene or polybutene.

In the fuel, the concentration of the additive will generally be at least 10 ppm and usually not more than 4,000 ppm, more usually in the range of from about 10 to about 1,000 ppm. In concentrates, the additive will generally be from about 1 to 50 weight percent, more usually from about 5 to 30 weight percent, and more generally not exceeding weight percent.

In gasoline fuels, other fuel additives may also be included such as anti-knock agents, e.g. tetramethyl lead, tetraethyl lead. Also included may be lead scavangers such as arylhalides, e.g. dichlorobenzene or alkylhalides, e.g. ethylene-dibromide. A non-volatile lubricating mineral oil, e.g. petroleum spray oil, particularly a refined naphthenic lubricating oil having a viscosity at F of 1,000 to 2,000 SUS, is a suitable oil-additive for the gasoline composition used with the hydrocarbylaminomethylenesulfonic acids of this invention and its use is preferred. Polymeric materials as mentioned above such as polyolefins and glycols such as polypropylene glycol can also be used. These oils are believed to act as the carrier for the additive and assist in removing and preventing deposits. They are employed in amounts of from about 0.05 to 0.5 percent by volume, based on the final gasoline composition.

EVALUATION 'to stand for two hours then photographed to record the results. The cutoff concentration is the lowest concentration where the solution is able to suspend or disperse a reasonable amount of the material, resulting in the solution having a dark and turbid appearance. An effective additive will have a low cutoff concentration and a poor additive will have a high cutoff concentratron.

The precipatated engine sludge was obtained from engines in actual service by scraping areas containing heavy deposits of sludge. The sludge was washed with hexane to remove oil and hydrocarbon-soluble substances. The mixture was centrifuged and the hexanesoluble fraction decanted. A second washing with hexane was performed. The insolubles were stirred with chloroform, centrifuged, and the chloroform decantate stripped on a solvent stripper to give a dry, black, granular material. This is the material used in the LDT. The dry material was dissolved in chloroform before use to give a solution of the desired concentration.

Base Fuel Containing Oil with I000 ppm of a Concentration of active additive was 250 ppm along a at 100 F.

naphthenic base oil having a viscosity of about I700 SU The results of Table I show that the hydrocarbylaminomethylenesulfonic acids of the present invention are superior to the hydrocarbyl-substituted amine parent compounds. In almost every case the cut-off point for the hydrocarbylaminomethylenesulfonic acid is lower than that of the starting amine. For example, the products of Examples 1 and 2 have cut-off points of 12.5 and 63 respectively, while the starting amine in Examples l and 2, (a polybutenyltetraethylene pentamine having a hydrocarbyl of number average molecular weight of about l,l90), has a cut-off point of 100 ppm. For this reason the hydrocarbyl aminomethylenesulfonic acid salts are expected to function as superior additives in hydrocarbon fuels.

The engine test results of Table l utilize a Waukesha ASTM/CFR single-cylinder engine. The test conditions are an engine speed of l,800 rpm, water temperature of2 l 2F, manifold vacuum of in. Hg, intake temperature of 95F, air fuel ratio is 14, ignition spark timing of l5BTC the base fuel is a laboratory simulation of Chevron commercial gasoline, and the base oil is a commercial Chevron W oil. The test is run for 12 hours. Upon completion of the test, intake valve is removed, washed with hexane and weighed. The deposits are removed with a wire brush and the valve reweighed. The difference between the two weights is the weight of the deposit. Of course, the smaller the amount of intake valve deposit the better the additive. As shown in Table I the base fuel containing the carrier oil without additive gave 147 g of deposit. The sulfonic acid salts of the present invention were as good as, or better than, the hydrocarbyl-substituted amine starting materials which are themselves known to be superior fuel additives.

Table II shows further Laboratory Dispersancy Tests (LDT) results for the hydrocarbyl-substituted starting amines and their aminomethylene-sulfonic acid.

In every case, the sulfonated hydrocarbyl amines are seen to be as good as, or surprisingly better than, the hydrocarbyl amine is dispersancy.

An additional engine test relating dispersancy power to engine cleanliness was carried out. This is the eight hour Engine Dispersancy Test (EDT) which is conducted in a 1972 Chevrolet 6-cylinder, 235-CID engine using as lubricating oil a 480 SUS at 100F neutral base oil containing a 15 mM/kg of zinc dithiophosphate. The test duration of eight hours is run under the following operating cycles. In stage one, which lasts for one minute, the engine speed is 700 rpm the load is 0 bhp, the water temperature is 1 10F and the oil temperature is 200F. In the second stage, which lasts for three minutes, the engine speed is 2500 rpm the engine load is bhp and the water and oil temperature are the same. At the completion of each test the used oil is analyzed for the amount of hexane insolubles. 10 ml of the oil is diluted to 50 ml with 0.45 micron-filtered hexane and filtered through a 3 micron filter followed by washing with hexane until oil-free and drying in an oven at 200F for 10 minutes. The amount of insolubles is reported is milligrams per 10 ml of used oil. A small amount of insoluble material indicates overall engine cleanliness.

In carrying out the EDT the starting amine used in Examples 4 and 5 was run at lower and lower concentrations in the fuel until the amine failed to suspend sludge in the engine oil and there was appreciable sludge formation. At 50 ppm, 38 mg of sludge was obtained from the average of 2 runs, while the base fuel, containing no additives, gave 42 mg of sludge. On the other hand, the product of Example 4 gave only 9.2 mg of sludge at the same concentration of 50 ppm (average of 2 runs). Thus, the superiority of the additives of the present invention in providing overall engine cleanliness is demonstrated.

These test results amply illustrate the superiority of the hydrocarbylaminomethylenesulfonic acids of the present invention as fuel additives. ln addition to those illustrated, other reaction products formed from these specified reagents of the present invention would also perform as superior fuel additives. It is not possible to attempt a comprehensive catalog of such reactants or to describe the invention in terms of specific chemical names of such reactions and reaction products without producing a voluminous disclosure. One skilled in the art could, by following the teaching of the invention herein described, select the proper reactants and reaction conditions to provide a useful composition for his purpose. While the character of this invention has been described in detail with several examples, this has been done by way of illustration rather than limitation. It would be apparent to those skilled in the art that numerous modifications and variations of the illustrative examples can be made in the practice of the invention within the scope of the following claims.

I claim:

1. A fuel composition comprising a major amount of a liquid hydrocarbonaceous fuel and in an amount sufficient to provide engine cleanliness a hydrocarbylaminomethylene-sulfonic acid, wherein said hydrocarbyl group contains at least 30 carbon atoms.

2. A fuel composition according to claim 1 wherein said hydrocarbylamino group is derived from a hydrocarbyl-substituted polyamine.

3. A fuel composition according to claim 2 wherein said hydrocarbyl group is derived from a polyolefin, itself derived from C -C olefins, with the proviso that ethylene is copolymerized with a higher olefin and said polyamine is an alkylene or polyalkylene polyamine of from 2 to 6 amino nitrogen atoms and of from 2 to 20 carbon atoms.

4. A fuel composition according to claim 3 wherein said hydrocarbyl group is a polyisobutenyl group of from 420 to 10,000 average molecular weight.

5. A fuel composition according to claim 1 wherein said hydrocarbylaminomethylenesulfonic acid is present in the fuel to the extent of from about 10 to 1000 PP 6. A hydrocarbylaminomethylenesulfonic acid which is useful as a fuel additive wherein said hydrocarbyl group contains at least 30 carbon atoms and is derived from a polyolefin, itself derived from C C olefins, with the proviso that ethylene is copolymerized with a higher olefin. 

1. A FUEL COMPOSITION COMPRISING A MAJOR AMOUNT OF A LIQUID HYDROCARBONACEOUS FUEL AND IN AN AMOUNT SUFFICIENT TO PROVIDE ENGINE CLEANLINESS A HYDROCARBYLAMINOMETHYLENESULFONIC ACID, WHEREIN SAID HYDROCARBYL GROUP CONTAINS AT LEAST 30 CARBON ATOMS.
 2. A fuel composition according to claim 1 wherein said hydrocarbylamino group is derived from a hydrocarbyl-substituted polyamine.
 3. A fuel composition according to claim 2 wherein said hydrocarbyl group is derived from a polyolefin, itself derived from C2-C6 olefins, with the proviso that ethylene is copolymerized with a higher olefin and said polyamine is an alkylene or polyalkylene polyamine of from 2 to 6 amino nitrogen atoms and of from 2 to 20 carbon atoms.
 4. A fuel composition according to claim 3 wherein said hydrocarbyl group is a polyisobutenyl group of from 420 to 10,000 average molecular weight.
 5. A fuel composition according to claim 1 wherein said hydrocarbylaminomethylenesulfonic acid is present in the fuel to the extent of from about 10 to 1000 ppm.
 6. A hydrocarbylaminomethylenesulfonic acid which is useful as a fuel additive wherein said hydrocarbyl group contains at least 30 carbon atoms and is derived from a polyolefin, itself derived from C2-C6 olefins, with the proviso that ethylene is copolymerized with a higher olefin. 